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GUANO, IN CONNECTION WITH FLORICULTURE. 
It might appear irrelevant to introduce the subject of Guano — the most poten- 
tial of all the so-called artificial manures of agriculture — in a work exclusively 
devoted to ornamental gardening; but as we hope shortly to make it evident that 
this wonderful substance contains all the elements of vegetable nutriment, and as, 
also, we find that gardeners and florists begin to bend their attention to it, we 
hope that farther apology will not be needed for our present attempt. 
Little more will be required than a faithful detail of the constituents of this 
substance to prove, beyond a doubt, that it must possess a power and energy 
exceeding those of common manures ; a fact which also points out the necessity 
of employing the utmost caution in its use. 
Analyses of various samples have been effected, and the results printed, since 
1804, when MM. de Fourcroy and Vauquelin examined the specimen introduced 
by Baron Yon Humboldt ; but it has been found that they all differ. At length, 
in 1843, Dr. Ure undertook an elaborate series of experiments, which appear to 
have demonstrated that the only species to be relied upon for perfection of quality 
are those of Peru and Bolivia. Assiduous researches have confirmed, to our own 
judgment, not only the general accuracy of the Doctor's analyses, but the com- 
parative worthlessness of samples obtained from other places ; therefore, we shall 
at once proceed to enumerate the chemical constituents of what we are assured are 
genuine samples of the Guano of Peru, undisturbed by that slow but progressive 
decomposition which inevitably results from exposure to air, moisture, and light. 
True Guano is of a palish drab-brown, tinted with a faint shade of red. It 
is heavier than water, bulk for bulk, and, to speak more correctly, its comparative 
specific gravity — water being 1.0 — is about 1.70, little more or less. Some 
specimens are interspersed with granular, whitish particles, which are evidently 
concretions of certain neutral salts ; and this circumstance leads to the first essential 
remark, namely, that the components of Guano can be arranged under two distinct 
heads : the soluble, or those which can readily be abstracted by pure water ; and 
the insoluble — that is, the substances which resist the solvent power of water, 
warm or cold. 
Guanos, in the condition in which they are imported, contain more or less 
water ; by drying at a heat not greater than that of boiling water, some samples 
lose eight or nine, others from fourteen to eighteen per cent. ; the latter may be 
said to be damp, a state which is, at the least, suspicious; for if it have not 
induced chemical action, it at least implies the presence of common salt in excess. 
The loss by heat being ascertained must be allowed for, in process 1, which 
consists of subjecting from one to two hundred grains (for the sake of a " per- 
centage " calculation) previously triturated in a wedgwood mortar, to the action 
VOL. XII. — NO. CXLI. D D 
